Manual Doors to Power- I have the whole door

I saw the other threads about this subject but none of them answered my question.I have a 90 LS with manual blah blah blah. I took the whole door off a 92 and put it on mine. windows don’t go up and down. My fuse block supports power windows, it even has the damn fues in it. do i just need to get the harness from the 92 and wire it to the back of my fuse panel. Or do i have to de-pin and re-pin my harness from the fuse panel. Can i splice into other wires and get away with that. Any help Would be greatly appreciated. Thank you
Justin:horny: